The primary objectives of this research are twofold. The first objective involves the extraction, isolation, identification, and quantitation of the alkaloids from the seeds of Sophora secundiflora (Ort.) Lag. ex DC. These seeds, commonly referred to as mescal beans, have an interesting folkloric use as a hallucinogen and are currently suspected as being drugs of abuse in our modern-day society. A general consensus indicates that the quinolizidine alkaloid cytisine is the psychoactive principle in this natural product. The successful completion of the first objective would confirm the presence of cytisine and expand considerably the knowledge concerning the alkaloid content of the mescal bean. Standard methods of fractionation, structure elucidation, and quantitation will be employed. The second objective involves a preliminary study of the psychoactivity of the total alkaloid mixture from the seed and how this activity relates to the individual alkaloids. Information derived from these studies will give some indication as to the psychotropic potential of the total alkaloid fraction of S. secundiflora seeds and a general idea of the relative involvement of each individual alkaloid. The psychoactivity of the total alkaloid fraction and the individual alkaloids will be screened using a simple, reliable, and novel mouse head-twitch model.